Many businesses use automated call processing services to process telephone calls received from customers. Automated call processing services are useful, for example, to connect a caller to a desired destination or obtain information quickly and easily. The caller typically is provided with an announcement and is requested to enter an appropriate sequence of keystrokes from the telephone keypad to respond to the announcement. For example, a caller who calls a large department store may be given the option of selecting a department from a menu recited over the phone. Dual tone multifrequency (DTMF) signaling enables the caller to use the telephone keypad as an input device to communicate menu selections through the telephone lines. In response to the caller's menu selections, the call is extended to the appropriate department of the department store.
DTMF signaling is required to obtain the full benefit of automated call processing services. However, not all telephone lines are configured to use DTMF signaling to communicate with the local central office. Many telephones use rotary or "dial pulse" signaling to communicate with the local central office. Thus, provisions must be made to accommodate both DTMF and dial pulse calls. Typically, a caller is requested to manually identify the type of signaling that the caller is using, for example, by striking a key on the telephone keypad if the caller has a "Touch-Tone.RTM." telephone (i.e., a telephone using DTMF signaling) to take advantage of automated call processing features. Callers using dial pulse signaling must wait a predetermined time-out period before being connected to an operator. This identification process produces call setup delays which increase telephone connect charges and may annoy telephone customers.